Water-cooled furnace wall



NM. 2& 119511 o. A. JOHNSON 2575528 WATER COOLD FURNACE WALL Filed Oct.2, 1946 2 SI-lEETS--SHEET 1 o. A. JOHNSON WATER COOLED FURNACE WALL 2SHEETS-SHEET 2 New. 20), 511

Filed Oct. 2, 1946 05691? doHNso/v Patented Nov. 20, 1951 WATER-COOLEDFURNACE WALL Oscar A. Johnson, Worcester, Mass., assignor to RileyStoker Corporation, Worcester, Mass., a. corporation of MassachusettsApplication October 2, 1946, Serial No. 700,'746

4 Claims.

This invention relates to water cooled furnace walls, and moreparticularly to an improved structure for supporting a substantiallyhorizontal header located adjacent a mel-supporting grate and arrangedto supply water to the lower ends of water Wall tubes.

In wall constructions of this type as heretofore employed difilcultieshave been encountered in providing adequate lateral support for the fuelbed and in preventing excessive air leakage into the furnace at thesides of the grate. Further more, the outer surface of the header has insome instances become cracked because of overheating, this trouble beingespecially pronounced in the case of headers with thick walls, asrequired to withstand high internal pressures. In certain priorarrangements, clinkers from the fuel bed have adhered to the wall andinterfered with combustion. such clinkers prevent the proper movement ofthe fuel bed on progressive feed grates, and the walls have often beendamaged by attempts at clinker removal.

It is accordingly one object of the invention to provide a headersupporting structure which will furnish adequate lateral support for thefuel bed and prevent excessive leakage of air between the grate and thewall.

It is a further object of the invention to provide a header supportingstructure arranged to be located adjacent one side of a fuel bed, and soconstructed as to protect the header from overheating and abrasion.

It is a further object of the invention to provide a header supportingstructure adapted to provide lateral support for a fuel bed and soconstructed that clinkers will not readily adhere thereto.

It is a further object of the invention to provide a header supportingstructure having parts arranged to support a fuel bed laterally and soconstructed that they can be readily replaced if necessary.

With these and other objects in View, as will be apparent to thoseskilled in the art, the invention resides in the combination of partsset forth in the specication and covered by the claims appended hereto.

Referring to the drawings illustrating one embodiment of the invention,and in which like reference num'erals indicate like parts, v

Fig. 1 is a longitudinal section through a stoke fired furnace having awater cooled side wall;

Fig. 2 is an enlarged View in section on the line 2-2 of Fig. l;

Flg. 3 is a perspective view of a block forming a portion of the Wall;

Fig. 4 is a perspectfve View of a different block forming a portion ofthe wall; and

Fig. 5 is a perspective view of the block shown in Fig. 4, taken from adifferent angle.

The embodiment illustrated comprises an end less grate o of well-knownconstruction which is supplied with fuel at its front end by means ofthe usualhopper l i. The upper run of the grate travels rearwardly inknown manner to support a bed of burning fuel, the ash being deposted ina pit !2 at the rear. Air for combustion is sup-*- plied beneath thefuel bed., preferably by forced draft, through the usual openings l4 atthe sides. The grate is installed within a furnace having a side Wall l5, a rear Wall !6, a front arch l8, and a rear arch [9. The rear arch |9includes a row of water tubes 20 which extend forwardly from atransverse rear header ZI. The side wall 15 includes a row of uprightwater tubes 23 which are connected at their lower ends to alongitudinally extending header 24. As shown in Fig. 2, this header isof circular cross-section, this construction being less expensive tomanufacture than other shapes and best adapted to withstand highinternal pressures. On the outer side of the header there are providedan upper horizontal flange 26 and a lower horizontal fiange 21. Theflange 26 provides a support for the refractory portion of the wall !5thereabove, and the fiange 21 is bolted to the flanged upper edge of averti-' cal plate 28.

` At the side of the grate IE] and beneath the side wall 15 there isprovided a longitudinally extending girder 30 having a flat horizontaltop plate 3 I. In known manner, this girder may form a portion of thesupporting framework for the grate. The header 24 is located directlyabove the plate 3 l and slightly spaced therefrom.

Means is provided to support the header 24, to protect the header fromoverheating and abrasion, and to confine the fuel bed laterally on thegrate o. For this purpose there is mounted on the top of the'girderplate 31 a continuous row or series of wedge-shaped metal blocks 33 withcomparatively thick inner portions which slightly overlap the adjacentedge of the grate. On the upper surface of each block there is formed alongitudinally extending rib 34 of substantial width and relativelyslightelevation. This rib is spaced from the inner edge of the block,and its upper surface is concave to make contact with the lower surfaceof the header 24 somewhat inwardly of the axis of the header. Atinstallation, a thin layer of heat-conductive cement 35 is laced in thegap or recess between the inner portion of each block 33 and theadjacent surface of the header. This cement may be of any suitablecomposition, for example, a mixture of iron powder and water glass. Theouter portion of each block is somewhat less in thickness than theminimum distance between the plate 3! and the header and on thesubstantially fiat upper surface of this outer portion there are mountedthree relatively small wedge-shaped metal blocks 31. These blocks haveconcave upper surfaces which make contact with the lower surface of theheader 24 somewhat outwardly of the axis of the header. It will be notedthat the bloeks 31 face oppositely to the blocks 33.

Releasable means is provided to connect the small wedge blocks 31 to themain blocks 33. As shown, each block 31 is constructed with a de-.

pending fiange 38 at its outer edge which overlaps the outer edge of the'block 33, this flange having a hole 39 therethrough to receive ahorizontal bolt 4! with a nut 42on its outer end. 'I'he outer portion ofthe block 33 is formed with three ?iF-.Slots 43 to receive the heads onthe inner ends of the bolts 41.

It will now be apparent that the blocks 33 and 3.1 provide a supportingsaddle for the header 24. 'Ifhe blocks 33 form a ledge along themarginal portion of the grate lil and support the fuel bed iaterally,while preventing excessive leakage of air between the grate and theheader. Although the thicl inner portions of the blocks 33, aresubjeeted to the heat of the fuel bed, they will nevertheless remain ata comparatively low temperature because of the rapid flow of heattherefrom through the cement 35 and the rib 34 to the metal wall of theheader 24 and thence to the water within the header. Clinkers will notadhere to these relatively cool blocks. These blocks also protect theheader 24 to a considerable extent from heat and abrasion. In case anyof the blocks 33 become damaged after a long life of service, they maybe easily replaced from the innerside of the wall 15 when the furnace isshut down. To permit replacement of the blocks, the nuts 42 should beremoved, access being had thereto by removal of the plate 28. Byreplacing the blocks one at a time, the header 24 will remain supportedin a proper manner.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. As an article of manufacture, a. wedgeshaped block having arelatively thick inner por: tion adapted to provide lateral support fora fuel bed, the block having a slightly elevated rib of substantialwidth extending along its upper surface and spaced from the inner edgeof the block, the rib having a concave upper surface for engagement withthe lower surface of a water Wal header.

2. As an article of manufacture, a wedgeshaped block having a relativelythick inner portion adapted to provide lateral support for a fuel bedand a relatively thin outer portion. the inner portion of the blockbeing shaped to provide -a concave upper surface for engagement with thelower surface of a water wall header. and the outer portion of the blockhaving a T-slot therein.

3. A support for a substantially horizontal furnace water wall headercomprising a wedgeshaped block having a relatively thick inner portionadapted to provide lateral support for a fuel bed, and a relativelysmall wedge-shaped block mounted on the outer portion of thefirstmentioned block, the two blocks racing oppositely and forming asaddle adapted to engage the lower surface of the header on oppositesides of its axis, the first-mentioned block having a slightly elevatedrib extending along its upper ur e a s ed from s nner ed e he' rib b nad o gas th h a ern suc a wer as to leave a gap or recess between theinner por, tion of the first-mentioned block and the, header for thereception of heat conductive cement.

4. A support for a substantially horizontal jure nace water wall headercomprising a Wedgeshaped block having a relatively thick inner por: tionadapted to provide lateral support for a fuel bed, and a relativelysmall wedge-shaped block mounted on the outer portion of the first:mentioned block, the two blocks facing oppositee ly and forming a saddleadapted to engage the lower surface of the header on opposite sides ofits axis, the outer portion of the first-mentioned block being providedWith a T-slot to receive the head of a. bolt, the relatively small blockhaving a depending flange provided with an opening through which thebolt extends in the outward direction.

OSCAR, A. JOHNSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,423,540 Poppenhusen July 25,1922 1,466,930 Cipra Sept. 4, 1923 1,477,898 Poppenhusen et al. Dec. 18,1923 1,485,952 Blunt Mar. 4, 1924 2241932 Rehm May 13, 1941 2375341Foresman May 15, 1945 '2393,707 Rehm -v- Jan. 29, 1946 FORE'IGN PATENTSNumber Country Date 405298 Great Britain Jan. 30, 1934:

